#include <iostream>
 
using namespace std;
 
class Line
{
public:
    void setLength( double len );
    double getLength( void );
    Line(double len);  // 这是构造函数
 
private:
    double length;
};
 
// 成员函数定义，包括构造函数
Line::Line(double len)
{
    cout << "Object is being created, length = " << len << endl;
    length = len;
}
 
void Line::setLength( double len )
{
    length = len;
}
 
double Line::getLength( void )
{
    return length;
}


int main( )
{
   Line line(10.0);
   // 获取默认设置的长度
   cout << "Length of line : " << line.getLength() <<endl;
   // 再次设置长度
   line.setLength(6.0); 
   cout << "Length of line : " << line.getLength() <<endl;
   return 0;
}